Route Availability (RA) is the system by which the permanent way and supporting works (bridges, embankments, etc) of the National Rail network of Great Britain are graded. All routes are allocated an RA number between 1 and 10.
Rolling stock is also allocated an RA (again between 1 and 10) and the RA of a train is the highest RA of any of its elements. The RA is primarily related to the axle load of the vehicle, although axle spacing is also taken into consideration. In practice it is the locomotive which governs where trains may operate, although many high capacity 4 axle wagons have high RAs when fully loaded. (When considering the operation of trains the loading gauge must also be considered.)
The RA of a train must not exceed the RA of the track except under strictly controlled circumstances.[1]
Contents |
Network Rail
Network Rail currently gives the allowed axle loadings as follows:[2]
| Route Availability | Axle Load |
|---|---|
| RA1–RA6 | ≤20.3 tonne |
| RA7-RA9 | ≤24.1 tonne |
| RA10 | ≤25.4 tonne |
| EU average | ≈22.5 tonne |
The information regarding route availability (RA) on this page comes from the British Rail (London Midland Region) Route Availability Guide, and the Freight Train Loads Book, both issued in 1969. It should be noted that several routes will have had their RA numbers changed since that time.
| Group Number | Mainline Classes | Shunters |
|---|---|---|
| 1 | Y14 | 01, 03, 04*, 11104, 15097 |
| 2 | 158, 220, 222 (five car) | 02, 04*, 05 |
| 3 | ||
| 4 | 15, 16, 17, 22, 221, 222 (seven car), 10800 | |
| 5 | 20, 23, 25, 27, 29, 31*, 37, 43, 55, 185 | 06, 08*, 09, 10, 11, 12 |
| 6 | 8K, D16/2, 24, 26, 31*, 33, 35, 40, 42, 47*, 48, 50, 52*, 53, 57, 71, 73, 81, 82, 83, 84, 85, 86, 87, 89 | 07, 08* |
| 7 | 44, 45, 46, 47*, 52*, 57, 58, 59, 66, 70, 74, 91 | |
| 8 | 67, 76 | 13 |
| 9 | ||
| 10 |
* Depending on sub-class, see individual article for details.
$ Discrepancy with original data.
Historical notes
Before nationalisation the Big Four railway companies had their own classification systems:
Great Western Railway
Each locomotive had a coloured disc painted on the cab side to indicate its route availability:
| Disc colour | Axle load (long tons & cwt) | Axle load (lb) | Axle load (t) | Notes |
|---|---|---|---|---|
| (no disc) | up to 14 long tons 0 cwt | 31,400 lb | 14.2 t | |
| Yellow disc | 14 long tons 0 cwt up to 16 long tons 0 cwt | 31,400–35,800 lb | 14.2–16.2 t | |
| Blue disc | over 16 long tons 0 cwt, up to 17 long tons 12 cwt | 35,800–39,400 lb | 16.2–17.9 t | |
| Red disc | over 17 long tons 12 cwt | 39,400 lb | 17.9 t | |
| Double Red disc | 22 long tons 10 cwt | 50,400 lb | 22.9 t | “King” class only |
- No. 111 'The Great Bear', the only 4-6-2 Pacific locomotive built and operated by the Great Western, was designated 'special red'.
See also
References
- ^ Safety & Standards Directorate, Railtrack PLC (December 2000). "Interface between Rail Vehicle Weights and Underline Bridges - Appendix C - Flow chart of Procedure for Permitting a Train to Run" (pdf). http://www.rgsonline.co.uk/docushare/dsweb/Get/Rail-41549/GERT8006.pdf. Retrieved 2008-08-17.
- ^ Network Rail Loading Gauge documentation
- ^ Ransome-Wallis (1966) p.181
- Ransome-Wallis, P. (1966). The Last Steam Locomotives of British Railways. Ian Allan Limited.
External links
- 2D53 Introduction to Route Availability and tables
- Route availability tables for Scotland
- Network Rail Information
- GE/RT8006 (Interface between Rail Vehicle Weights and Underline Bridges)
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